Maybe this is what's going on inside the zombies' heads. You know, this state of raving, braindead euphoria where endless streams of consciousness are the norm, and there's little genuine engagement with the world around them. People who've had near death experiences describe "the light" as a feeling of cosmic bliss washing over them - isn't zombiehood one prolonged near death experience?

that's a excellent thought, but the flesh eating isn't something that happens to most people.It would suck, to be stuck in that feeling of bliss and then have yourself jarred out of it only to find out you've been feasting on the poor living souls of your neighborhood.

To be eating people you have to be in some sort of delirium. Charlie Sheen zombies make as much sense as anything else.There's a common "no higher brain functions" thing going about zombies, but the human brain is built in such a way that nothing is done without such functions. The last stage of degenerative diseases that destroy those parts of the brain isn't "mindless rampaging beast terrorising the city" but "drooling on oneself in a bed". It's logical that zombies would have some sort of thoughts, although they can be completely disconnected from reality, not necessarily follow one another, might not end in forming memories or involve a sense of identity. And when it comes to emotions, they're the language of instinct, more basic, more difficult to lose, zombies could very well be feeling pleasure when they catch and eat a person. They might even express it, making zombies even more creepy...

Zerkers seem to display that. Also prolonged sensations, especially unpleasent ones, can bring on wild erratic and sometimes violent behaviors. Even things like itching can cause people to crack eventually. Some persistant feelinging could cause the zombie flesheating desire. Maybe do to something like prions satiating the feeling at least for a very brief time.

I'm often struck by how much effort this community puts into possible explanations for zombies which agree with science. Definitionally, there won't really be one: "Zombie (n) 1. The body of a dead person given the semblance of life, but mute and will-less, by a supernatural force, usually for some evil purpose."

Even leaving aside the "supernatural" qualifier of that definition, necrotic tissues can't function due to lack of oxygen. Chemically speaking, only zombies with functioning respiratory systems could supply energy to their muscles in order to move. Alternative sources of energy (e.g. solar, nuclear, "a virus," or whatever) lack plausibility (although photosynthesis might provide enough energy for the occasional twitch, if you like bright green zombies).

The only zombies that make sense are 1. those which aren't truly zombies, but rather humans with altered cognition, or 2. undead beings of supernatural origin. Given the greater immediacy of a modern day setting, and common tropes like contagious viral strains, crazy people seem to be the best bet. But don't knock magical origins for the evil undead; nothing says "zombie" quite like glowing eyes, and cemeteries are rockin' cool.

Dethklok, you missed one important thing: suspension of disbelief.Most science-fiction, horror and of course fantasy will cut round the corners with their science, and the viewer accepts those alternate rules in order to enjoy the story.The art of fictional pseudo-science is one that is fun to elaborate on between fans. The idea isn't to come up with something that is literally true, but something that is close enough for a fiction lover's mind to accept.